I. Field of the Invention
The invention relates to torque rods, and more particularly, to torque rods for heavy duty vehicles composed of a polymerizable composite material. Such rods are typically used to interconnect elements of the vehicle's drive train with the vehicle's chassis to relieve strain and to stabilize the drive train while the vehicle is accelerating, stopping, or articulating from road and terrain conditions. The rods may be fixed axially, laterally or obliquely relative to the differential housing and the chassis.
II. Description of the Prior Art
Torque rods are well known for use in heavy duty motor vehicles, particularly on those vehicles with tandem axle suspensions. Present rods are composed substantially of steel, and include a steel shaft with two straddle mount ends each having a transverse aperture defined therein forming a socket. The straddle mount ends have mounting flanges with apertures defined therein for attachment to selected points on the chassis and drive train.
There are two basic types of straddle mount ends. The first type includes a central ball with two outwardly extending mounting flanges fitted into each socket. Interfitted between the ball and the socket is an insulating, lining material composed of a plastic or a metal. The ball and related liner is fixed into the socket by one or more rings that are of the snap ring design, press fitted, staked or flanged into position. This construction allows for full rotation and high angulation of the ball relative to the socket.
The second type of straddle mount end includes a cylindrical pin body with two outwardly extending flanges fitted into each socket. Interfitted between the pin body and the socket is an insulating, lining material composed of a rubber. On assembly the rubber is deformed so as to become seized to the inner surface of the socket and the surface of the cylindrical pin body. This construction restricts both angulation and rotation of the pin relative to the socket.
There are several disadvantages of the prior art which render conventional constructions undesirable. First, the conventional torque rod is heavy, weighing about 20 pounds. Second, the conventional rod is difficult and costly to manufacture, requiring virtually flawless steel castings or forgings, expert machining and difficult assembly with heavy presses and the like. Third, because of the difficulty of manufacture and the high cost of necessary materials, the conventional rod is costly to produce and replace. Fourth, the insulating, lining material conventionally interfitted between the ball and the socket is prone to wear. And fifth, the length of the conventional torque rod is incapable of being conveniently adjusted, thereby virtually eliminating interchangability between vehicle brands.